Gas turbine engines are used in a wide range of applications, such as aircraft engines and auxiliary power units. In a gas turbine engine, air is compressed in a compressor and mixed with fuel and ignited in a combustor to generate hot combustion gases, which flow downstream into a turbine section. In a typical configuration, the turbine section includes rows of airfoils, such as stator vanes and rotor blades, disposed in an alternating sequence along the axial length of a generally annular hot gas flow path. The rotor blades are mounted at the periphery of one or more rotor disks that are coupled in turn to a main engine shaft. The hot combustion gases are delivered from the engine combustor to the annular hot gas flow path, thus resulting in rotary driving of the rotor disks to provide an engine output.
Due to the high temperatures in many gas turbine engine applications, it is desirable to regulate the operating temperature of certain engine components, particularly those within the mainstream hot gas flow path, in order to prevent overheating and potential mechanical issues attributable thereto. As such, it is desirable to cool the rotor blades and stator vanes in order to prevent damage and extend useful life. One mechanism for cooling turbine airfoils is to duct cooling air through internal passages and then vent the cooling air through holes formed in the airfoil. The holes are typically formed uniformly along a line substantially parallel to the leading edge of the airfoil and at selected distances from the leading edge to provide a film of cooling air over the convex side of the airfoil. Other rows of cooling holes or an array of holes may be formed in the airfoil components depending upon design constraints. In some instances, the cooling of engine components in an efficient and effective manner remains a challenge.
Accordingly, it is desirable to provide a gas turbine engine with components having improved film cooling. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.